Topcoder Moves from IBM Informix to Postgres

After more than two decades at Topcoder, I’ve seen our platform evolve in countless ways. But one thing remained constant: IBM Informix. For 24 years, every piece of legacy data — from challenges to submissions to Online Review — was stored in Informix. It’s been the backbone of our platform, but also one of the biggest anchors holding us back.

This November, we’re saying goodbye to Informix and simplifying the entire Topcoder platform in the process.

The Old Way: A Patchwork of Systems

Our original platform was a mix of technologies built over time.

• Data Stores:

  • v3 services → Informix

  • v5 services → a mix of ElasticSearch, Postgres, Neo4j, MySQL, and DynamoDB

  • Some services (like Challenge API) stored the same data in multiple places, e.g., ElasticSearch and DynamoDB

This made maintenance extremely difficult. If a record went bad, we first had to figure out which data store was the “real” one before we could even start debugging.

• Code:

  • v3 services → Java

  • v5 services → JavaScript, but with inconsistent Node versions, dependencies, and coding styles

  • Kafka usage → each microservice had its own approach

• Data Syncing:
  To keep Online Review alive, we had to constantly sync data between v5 services and Informix. We did this with Kafka messages, 20+ processors, and a highly complex Data Access Layer (DAL) built on Google RPC. Debugging issues across these moving pieces was… not fun.

• Reporting:
  Our data warehouse relied on a massive, SQL-heavy codebase. There are thousands and thousands of lines of SQL queries that run to translate data from the main database to the Redshift data warehouse. These loaders ran on specific schedules on a dedicated EC2 instance, orchestrated by cronjobs or the at utility. When things failed, troubleshooting could take hours or even days.

All in all, we had an architecture that worked, but was fragile, inconsistent, and hard to maintain. 

The New Way: One Database, One Stack

The new Topcoder platform simplifies all of this.

• One Source of Truth:
  A single Postgres database powers everything. No more chasing down which data store has the right record.

• One Tech Stack:
  All new services are written in TypeScript, with Prisma for database access.
  This brings consistency across microservices and makes support far simpler.

• Cleaner Architecture:

  • 20+ old processors → gone

  • DAL complexity → gone

  • ElasticSearch, DynamoDB, MySQL, Neo4j → gone

With Postgres at the center, every service is streamlined, easier to debug, and easier to scale.

Why This Matters for Everyone

You don’t need to be a developer to feel the benefits of this change.

By moving to a single, modern database and standardizing all our services on the same codebase, we’re making the Topcoder platform:

• Faster: pages and features will load more quickly because the platform no longer has to juggle data across multiple old systems.

• More Reliable: fewer moving parts means fewer things that can break.

• Easier to Improve: members and our internal engineers can add new features and fix bugs much faster than before, because the codebase is simpler and consistent.

• Easier Local Development:
  The new services can be easily deployed locally for development and testing. With the old stack, spinning up a working environment was nearly impossible because of all the dependencies across Informix, ElasticSearch, DynamoDB, and other systems. This made it extremely difficult to run challenges and for new engineers to get up to speed on the platform.

Built by the Community, for the Community

The best part of this transformation? It wasn’t done behind closed doors.

Throughout 2025, we ran over 100 challenges to build the new platform. Our member community designed databases, APIs, UIs, migration scripts, unit tests, and more.

This is proof that Topcoder isn’t just for our customers. We use it to solve our own toughest problems.

A New Review App

With Informix going away, Online Review is also retiring. In its place, we’ve built a new Review Application.

The overall flow will feel familiar, but we’ve added some modern touches:

• Drag-and-drop file uploads in review comments and appeals

• Markdown support for comments, appeals, and appeal responses

• A cleaner, more intuitive interface

This is new code, but rest assured: the functionality you rely on is there, plus some nice improvements. 

Cutover Day: November 3rd

On November 3rd, we’ll migrate all data from Informix, ElasticSearch, MySQL, DynamoDB, and Neo4j into Postgres. We’ll also update our AWS routing to point to the new apps and services.

There may be some downtime as this cutover happens, but it shouldn’t be for more than 6 hours. We’ll try to schedule challenges and other things to take this downtime into account.

Looking Ahead

Moving off Informix isn’t just about saying goodbye to legacy systems. It’s about setting up Topcoder for the next 20 years.

With a cleaner architecture, modern tools, and a unified data source, we can innovate faster, support our community better, and keep building the future of work.

It’s the end of an era — and the beginning of a simpler, stronger Topcoder.