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Practical T24 writing on the topics that matter in production — AA, TPH, TAFC to TAFJ migrations, COB, and careers. Written from real experience, not vendor documentation.
Featured articles
The cornerstone reads every T24 professional should know.
AA fundamentals
What on Earth is AA? Arrangement Architecture Explained
A plain-English introduction to Arrangement Architecture — Product Families, Property Classes, Arrangements, and why changes do nothing until you Proof and Publish.
COB fundamentals
What Is COB in T24? Close of Business Explained
A plain-English introduction to Close of Business (COB) in Temenos T24 — what it does, why it matters, what the batch actually processes, and what to do when it does not complete.
T24 fundamentals
What Is SWIFT in T24? A Plain-English Introduction
A plain-English introduction to SWIFT messaging in Temenos T24 — what SWIFT actually does, how messages get in and out, what MT and MX mean, and why your payment is stuck in a repair queue.
TPH fundamentals
What TPH Actually Does and Why It Is Hard to Learn
The moment TPH becomes real is usually around 2am during a production incident. Payments are not going out. Thirty people are on a call. This is what you actually need to know before that call happens.
New to T24? Start Here
The fundamentals every T24 professional should know — OFS, AA, COB, and SWIFT explained in plain English.
T24 fundamentals
What Is OFS in T24? Open Financial Services Explained
OFS is how the outside world talks to T24. A plain-English introduction to the message structure, request types, OFS.SOURCE configuration, security, and what breaks when integrations go wrong.
ReadAA fundamentals
What on Earth is AA? Arrangement Architecture Explained
A plain-English introduction to Arrangement Architecture — Product Families, Property Classes, Arrangements, and why changes do nothing until you Proof and Publish.
ReadCOB fundamentals
What Is COB in T24? Close of Business Explained
A plain-English introduction to Close of Business (COB) in Temenos T24 — what it does, why it matters, what the batch actually processes, and what to do when it does not complete.
ReadT24 fundamentals
What Is SWIFT in T24? A Plain-English Introduction
A plain-English introduction to SWIFT messaging in Temenos T24 — what SWIFT actually does, how messages get in and out, what MT and MX mean, and why your payment is stuck in a repair queue.
ReadGoing Through a Migration?
Essential reading for anyone moving from TAFC to TAFJ — differences, debugging, and deployment.
TAFC to TAFJ
Why a Select That Worked in TAFC Returned Nothing in TAFJ
The routine compiled. It ran. It produced an output file with a header and a footer. There were no detail lines. A real migration debugging case involving derived DICT fields and the TAFJ selection layer.
ReadTAFC to TAFJ
TAFJ DBTools: The SELECT Replacement Nobody Tells You About
In TAFC you ran a SELECT in the command line. In TAFJ that is gone. The replacement is DBTools — a separate console with its own users, its own modes, and a 200-row default limit nobody mentions.
ReadTAFC to TAFJ
TAFJ Compilation: Why Your Changes Aren't Doing Anything
In TAFJ, editing source code changes nothing until you compile, package, and deploy. The full pipeline: tCompile, tIntegrate, tComponentSplitter, tMerge — and what each one does.
ReadTAFC to TAFJ
jBC vs Design Studio in TAFJ: Which One Should You Actually Use?
The honest answer is: it depends on what you are building. A practical guide to choosing between jBC and Design Studio in TAFJ, with a simple decision rule that works in production.
ReadIn Production Support?
Day-to-day survival guides — incident response, record locking, log analysis, and batch verification.
Production support
Five Things to Check Before Escalating a T24 Incident
The difference between a junior analyst and an experienced one is often ten minutes and a short checklist. Five questions to answer before you pick up the phone.
ReadProduction support
T24 Record Locking: What a Stuck Lock Means and How to Clear It
A practical guide to record locking in T24: why locks exist, when they become a support problem, and how to investigate before clearing them.
ReadTAFJ operations
TAFJ Log Files: Where to Look When Something Goes Wrong
TAFJ distributes its logs across six different locations maintained by different parts of the stack. Where each one lives, what it covers, and the order to check them in — before an incident makes the question urgent.
ReadCOB and support
Why Batch Success Can Be Misleading in T24
A practical T24 operations guide to proving that a completed batch produced the expected business outcome, not only a successful return status.
ReadIntegration & Production support
Trace a Failed OFS Request Through TAFJ and JBoss Logs
A systematic diagnostic sequence for tracing a failed OFS request from entry point to T24 processing — transport, authentication, syntax, validation, posting, and response-delivery failure stages, with log sources and redaction guidance.
ReadArrangement Architecture
Everything about AA — properties, interest, COB replay, and product configuration.
AA fundamentals
What on Earth is AA? Arrangement Architecture Explained
A plain-English introduction to Arrangement Architecture — Product Families, Property Classes, Arrangements, and why changes do nothing until you Proof and Publish.
ReadAA fundamentals
AA Interest Explained: How Interest Actually Works in T24
Interest in AA is not a field you fill in. It is a property class, a product condition, a payment schedule, and an accrual process — all of which have to be correct, or the wrong number appears silently.
ReadAA and COB
COB and AA: Why Activities Replay and When That Goes Wrong
Reverse-replay is the most common source of AA production incidents. A back-dated change triggers a full recalculation of the arrangement history. What it does, what triggers it, and how to diagnose it.
ReadAA deep dive
AA Property Classes in Practice: Interest, Charges, and the Ones That Trip Everyone Up
AA Property Classes are the categories of behaviour that define what a product can do. Account, Charges, Accounting, Balances, Settlement, Limit — what each one controls, the configuration choices that silently produce wrong results, and how to diagnose them.
ReadTPH Payments
Production payment handling — diagnosis, repair queues, and lifecycle.
TPH fundamentals
What TPH Actually Does and Why It Is Hard to Learn
The moment TPH becomes real is usually around 2am during a production incident. Payments are not going out. Thirty people are on a call. This is what you actually need to know before that call happens.
ReadTPH diagnosis
How to Diagnose a Failed TPH Payment: End-to-End Guide
Trace a failed TPH payment from arrival through validation, routing, posting, scheme handoff, acknowledgement, repair, and retry while controlling duplicate risk.
ReadTAFC → TAFJ Migration
What changes between TAFC and TAFJ — compilation, DBTools, descriptors, and real debugging cases.
TAFC to TAFJ
Why a Select That Worked in TAFC Returned Nothing in TAFJ
The routine compiled. It ran. It produced an output file with a header and a footer. There were no detail lines. A real migration debugging case involving derived DICT fields and the TAFJ selection layer.
ReadTAFC to TAFJ
TAFJ DBTools: The SELECT Replacement Nobody Tells You About
In TAFC you ran a SELECT in the command line. In TAFJ that is gone. The replacement is DBTools — a separate console with its own users, its own modes, and a 200-row default limit nobody mentions.
ReadTAFC to TAFJ
TAFJ Compilation: Why Your Changes Aren't Doing Anything
In TAFJ, editing source code changes nothing until you compile, package, and deploy. The full pipeline: tCompile, tIntegrate, tComponentSplitter, tMerge — and what each one does.
ReadTAFC to TAFJ
TAFJ Descriptor Limitations: Why Old TAFC Logic Breaks in TAFJ
The DICT item still exists. The routine compiles. But the runtime behaviour is different. A practical guide to descriptor-driven logic in TAFJ and why it is not what it looks like.
ReadTAFJ operations
TAFJ Deployment Explained — WAR Files, Cache, and Verification
A WAR file was deployed, the logs show success, but the browser still shows old behaviour. Why? Because deployment and activation are not the same thing. A practical guide to the TAFJ deployment lifecycle, cache layers, and how to verify what is actually running.
ReadClose of Business
How COB works in T24 — batch processing, AA interactions, and what to check when it does not complete.
COB fundamentals
What Is COB in T24? Close of Business Explained
A plain-English introduction to Close of Business (COB) in Temenos T24 — what it does, why it matters, what the batch actually processes, and what to do when it does not complete.
ReadAA and COB
COB and AA: Why Activities Replay and When That Goes Wrong
Reverse-replay is the most common source of AA production incidents. A back-dated change triggers a full recalculation of the arrangement history. What it does, what triggers it, and how to diagnose it.
ReadCOB and support
Why Batch Success Can Be Misleading in T24
A practical T24 operations guide to proving that a completed batch produced the expected business outcome, not only a successful return status.
ReadIntegration & APIs
OFS, SWIFT, REST, IBM MQ, IRIS, Kafka — how T24 talks to the outside world.
T24 fundamentals
What Is OFS in T24? Open Financial Services Explained
OFS is how the outside world talks to T24. A plain-English introduction to the message structure, request types, OFS.SOURCE configuration, security, and what breaks when integrations go wrong.
ReadT24 fundamentals
What Is SWIFT in T24? A Plain-English Introduction
A plain-English introduction to SWIFT messaging in Temenos T24 — what SWIFT actually does, how messages get in and out, what MT and MX mean, and why your payment is stuck in a repair queue.
ReadIntegration architecture
OFS vs API vs Batch Interfaces: When to Use What in T24
A practical guide to T24's three integration paradigms — OFS for real-time, APIs for modernisation, and batch for volume — with decision criteria for each.
ReadIntegration architecture
IBM MQ with Temenos T24: Messaging Patterns That Work
How IBM MQ and other message queue technologies integrate with T24 for reliable, asynchronous, and guaranteed-delivery messaging patterns.
ReadIntegration & Production support
Trace a Failed OFS Request Through TAFJ and JBoss Logs
A systematic diagnostic sequence for tracing a failed OFS request from entry point to T24 processing — transport, authentication, syntax, validation, posting, and response-delivery failure stages, with log sources and redaction guidance.
ReadIntegration support
T24 Messaging Queue Has Messages But No Consumer: Diagnostic Guide
A systematic diagnostic sequence for when a T24 messaging queue has depth but no consumer is processing — distinguishing inactivity from connectivity, channel, application, retry, and dead-letter conditions.
ReadOFS troubleshooting
OFS Response Errors: Diagnose Failures by Processing Stage
Diagnose T24 OFS response failures by transport, authentication, syntax, validation, authorisation, posting, and response-delivery stage.
ReadProduction Support
Incident response, record locking, log files, and the five checks before you escalate.
Production support
Five Things to Check Before Escalating a T24 Incident
The difference between a junior analyst and an experienced one is often ten minutes and a short checklist. Five questions to answer before you pick up the phone.
ReadProduction support
T24 Record Locking: What a Stuck Lock Means and How to Clear It
A practical guide to record locking in T24: why locks exist, when they become a support problem, and how to investigate before clearing them.
ReadTAFJ operations
TAFJ Log Files: Where to Look When Something Goes Wrong
TAFJ distributes its logs across six different locations maintained by different parts of the stack. Where each one lives, what it covers, and the order to check them in — before an incident makes the question urgent.
ReadIntegration & Production support
Trace a Failed OFS Request Through TAFJ and JBoss Logs
A systematic diagnostic sequence for tracing a failed OFS request from entry point to T24 processing — transport, authentication, syntax, validation, posting, and response-delivery failure stages, with log sources and redaction guidance.
ReadCareer & Industry
Navigating the T24 job market, interviews, certifications, and the industry landscape.
Career
The T24 Interview Process: What They Actually Ask and What You Should Actually Say
A practical guide to interviewing for T24 roles — what the questions really mean, what answers actually work, and how to navigate the unique absurdity of T24 interviews.
ReadCareer
The T24 Career Circular Trap: How to Get T24 Experience When Every Role Requires It
Every T24 job says experience required. Every new entrant asks how to get it. The four paths that actually work — internal transfer, consultancy entry, Temenos graduate programme, and operations entry — and why the front door is not the only door.
ReadCareer
How to Position Yourself as a T24 Migration Specialist
The TAFC-to-TAFJ migration wave is still moving through the industry. Consultants who can credibly pitch migration expertise are commanding better contracts. The three knowledge layers, how to frame your experience, and the mistakes that make experienced people sound junior.
ReadIndustry shift
MT to MX: What Retail Banks Need to Know About the ISO 20022 Migration
The SWIFT MT to MX (ISO 20022) migration is coming for retail banks. What changes, what stays the same, and what T24 teams need to do before the deadline.
ReadAll articles
Browse or search the full library — 43 articles and counting.
AA fundamentals
What on Earth is AA? Arrangement Architecture Explained
A plain-English introduction to Arrangement Architecture — Product Families, Property Classes, Arrangements, and why changes do nothing until you Proof and Publish.
AA fundamentals
AA Interest Explained: How Interest Actually Works in T24
Interest in AA is not a field you fill in. It is a property class, a product condition, a payment schedule, and an accrual process — all of which have to be correct, or the wrong number appears silently.
AA and COB
COB and AA: Why Activities Replay and When That Goes Wrong
Reverse-replay is the most common source of AA production incidents. A back-dated change triggers a full recalculation of the arrangement history. What it does, what triggers it, and how to diagnose it.
AA deep dive
AA Property Classes in Practice: Interest, Charges, and the Ones That Trip Everyone Up
AA Property Classes are the categories of behaviour that define what a product can do. Account, Charges, Accounting, Balances, Settlement, Limit — what each one controls, the configuration choices that silently produce wrong results, and how to diagnose them.
TPH fundamentals
What TPH Actually Does and Why It Is Hard to Learn
The moment TPH becomes real is usually around 2am during a production incident. Payments are not going out. Thirty people are on a call. This is what you actually need to know before that call happens.
TPH diagnosis
How to Diagnose a Failed TPH Payment: End-to-End Guide
Trace a failed TPH payment from arrival through validation, routing, posting, scheme handoff, acknowledgement, repair, and retry while controlling duplicate risk.
TAFC to TAFJ
Why a Select That Worked in TAFC Returned Nothing in TAFJ
The routine compiled. It ran. It produced an output file with a header and a footer. There were no detail lines. A real migration debugging case involving derived DICT fields and the TAFJ selection layer.
TAFC to TAFJ
TAFJ DBTools: The SELECT Replacement Nobody Tells You About
In TAFC you ran a SELECT in the command line. In TAFJ that is gone. The replacement is DBTools — a separate console with its own users, its own modes, and a 200-row default limit nobody mentions.
TAFC to TAFJ
TAFJ Compilation: Why Your Changes Aren't Doing Anything
In TAFJ, editing source code changes nothing until you compile, package, and deploy. The full pipeline: tCompile, tIntegrate, tComponentSplitter, tMerge — and what each one does.
T24 fundamentals
What Is OFS in T24? Open Financial Services Explained
OFS is how the outside world talks to T24. A plain-English introduction to the message structure, request types, OFS.SOURCE configuration, security, and what breaks when integrations go wrong.
TAFC to TAFJ
jBC vs Design Studio in TAFJ: Which One Should You Actually Use?
The honest answer is: it depends on what you are building. A practical guide to choosing between jBC and Design Studio in TAFJ, with a simple decision rule that works in production.
T24 fundamentals
Why T24 Became Temenos Transact (And Why You Still Call It T24)
The rebrand story — what actually changed, what did not, and what the architectural direction means for professionals who have spent years working with T24.
TAFC to TAFJ
TAFJ Descriptor Limitations: Why Old TAFC Logic Breaks in TAFJ
The DICT item still exists. The routine compiles. But the runtime behaviour is different. A practical guide to descriptor-driven logic in TAFJ and why it is not what it looks like.
COB fundamentals
What Is COB in T24? Close of Business Explained
A plain-English introduction to Close of Business (COB) in Temenos T24 — what it does, why it matters, what the batch actually processes, and what to do when it does not complete.
T24 fundamentals
What Is SWIFT in T24? A Plain-English Introduction
A plain-English introduction to SWIFT messaging in Temenos T24 — what SWIFT actually does, how messages get in and out, what MT and MX mean, and why your payment is stuck in a repair queue.
Industry shift
MT to MX: What Retail Banks Need to Know About the ISO 20022 Migration
The SWIFT MT to MX (ISO 20022) migration is coming for retail banks. What changes, what stays the same, and what T24 teams need to do before the deadline.
Infrastructure
Containerization and Cloud for T24: Docker and K8s
A high-level look at running Temenos Transact in containers, orchestrating TAFJ workloads with Kubernetes, and migrating to AWS, Azure, or Temenos Cloud.
Architecture
API Architecture in T24: From OFS to IRIS to REST
An overview of API patterns in Temenos Transact — from classic OFS and SOAP to the modern Temenos Integration Framework (IRIS) and REST APIs, with guidance on when to use each approach and how they compare to event-driven integration.
Platform governance
TEF Extensibility vs Legacy L3 Modifications: Why Upgrade-Safe Wins
What the Temenos Extensibility Framework (TEF) is, why it replaces legacy L3 core modifications, and how it makes T24 upgrades faster, safer, and cheaper.
Career
The T24 Interview Process: What They Actually Ask and What You Should Actually Say
A practical guide to interviewing for T24 roles — what the questions really mean, what answers actually work, and how to navigate the unique absurdity of T24 interviews.
Career
The T24 Career Circular Trap: How to Get T24 Experience When Every Role Requires It
Every T24 job says experience required. Every new entrant asks how to get it. The four paths that actually work — internal transfer, consultancy entry, Temenos graduate programme, and operations entry — and why the front door is not the only door.
Production support
Five Things to Check Before Escalating a T24 Incident
The difference between a junior analyst and an experienced one is often ten minutes and a short checklist. Five questions to answer before you pick up the phone.
Operations
The First 30 Days After a TAFJ Go-Live: What the Operations Team Actually Faces
The project team has gone. The environment is live. A practical account of what operations teams encounter in the first month after a TAFJ cutover — and what to do about it.
Migration risk
How to Tell If Your T24 Migration Is in Trouble Before It's Too Late
The status report says green. The project team says on track. Six warning signals that tell you what the dashboard does not — and the questions that surface the truth.
Career
How to Position Yourself as a T24 Migration Specialist
The TAFC-to-TAFJ migration wave is still moving through the industry. Consultants who can credibly pitch migration expertise are commanding better contracts. The three knowledge layers, how to frame your experience, and the mistakes that make experienced people sound junior.
Integration architecture
OFS vs API vs Batch Interfaces: When to Use What in T24
A practical guide to T24's three integration paradigms — OFS for real-time, APIs for modernisation, and batch for volume — with decision criteria for each.
Integration architecture
IBM MQ with Temenos T24: Messaging Patterns That Work
How IBM MQ and other message queue technologies integrate with T24 for reliable, asynchronous, and guaranteed-delivery messaging patterns.
Integration architecture
Real-Time Event Architecture in T24: IRIS and Kafka
How T24's event-driven architecture works with IRIS, Kafka, and publish-subscribe patterns to enable real-time integration.
Integration architecture
Legacy Host Integration with T24: Mainframes, AS/400
How T24 integrates with mainframe and legacy host systems — the protocols, patterns, and practical realities of connecting old and new.
Production support
T24 Record Locking: What a Stuck Lock Means and How to Clear It
A practical guide to record locking in T24: why locks exist, when they become a support problem, and how to investigate before clearing them.
TAFJ operations
TAFJ Log Files: Where to Look When Something Goes Wrong
TAFJ distributes its logs across six different locations maintained by different parts of the stack. Where each one lives, what it covers, and the order to check them in — before an incident makes the question urgent.
COB and support
Why Batch Success Can Be Misleading in T24
A practical T24 operations guide to proving that a completed batch produced the expected business outcome, not only a successful return status.
Integration architecture
File Interfaces That Still Run Banks: The Unsung Heroes of T24 Integration
Why flat files, CSV exports, and batch file transfers remain the backbone of T24 integration — and why they are not going anywhere.
Getting started
What Junior T24 People Should Learn First
New to T24? The fastest way to get useful is not to memorise commands. It is to understand flow, state, and what healthy looks like before the details have anywhere to stick.
Integration operations
TAFJ JMS Paging Store Growing Fast — Diagnosis and Safe Next Checks
When the ActiveMQ Artemis paging-store directory grows during TAFJ operation, the first question is whether it is expected or a signal of a deeper issue. A practical guide to reading the evidence safely — queue metrics, consumer checks, safe containment, and when to escalate.
Integration & Production support
Trace a Failed OFS Request Through TAFJ and JBoss Logs
A systematic diagnostic sequence for tracing a failed OFS request from entry point to T24 processing — transport, authentication, syntax, validation, posting, and response-delivery failure stages, with log sources and redaction guidance.
TAFJ operations
TAFJ Deployment Explained — WAR Files, Cache, and Verification
A WAR file was deployed, the logs show success, but the browser still shows old behaviour. Why? Because deployment and activation are not the same thing. A practical guide to the TAFJ deployment lifecycle, cache layers, and how to verify what is actually running.
COB operations
T24 COB After a Database Restore — What to Check
A practical guide to the checks to make when T24 COB does not continue normally after a database restore — state verification, evidence gathering, validation, and reconciliation.
Production support
T24 Database Storage Growth: Data, Logs, and What to Watch
A practical guide to T24 database storage growth — the difference between data and transaction-log storage, why growth and reusable space are not the same thing, and what support teams should monitor before capacity becomes a problem.
Production support
T24 Disaster Recovery Validation Checklist: How to Know a Restored Service Is Actually Safe
A practical, environment-neutral guide to validating a restored T24 service — covering infrastructure, database, application, integration, batch state, business validation, and sign-off evidence.
Integration support
T24 Messaging Queue Has Messages But No Consumer: Diagnostic Guide
A systematic diagnostic sequence for when a T24 messaging queue has depth but no consumer is processing — distinguishing inactivity from connectivity, channel, application, retry, and dead-letter conditions.
Integration troubleshooting
E-Advice PDF Response Troubleshooting: Parsing Errors and Content Failures
When an E-Advice PDF arrives with the wrong content — or no content at all — the problem is almost never the PDF itself. A systematic guide to diagnosing parser errors caused by unexpected response content, covering response type, headers, encoding, upstream error pages, document generation, and transport.
OFS troubleshooting
OFS Response Errors: Diagnose Failures by Processing Stage
Diagnose T24 OFS response failures by transport, authentication, syntax, validation, authorisation, posting, and response-delivery stage.