Senior Backend Engineer
(Node & PostgreSQL)

Nobody has ever opened a travel app to admire the API. They open it because a train leaves in forty minutes and they need to know which platform. Everything we have promised a traveller resolves, eventually, into a query that has to come back in under three hundred milliseconds. That part is yours.

OneCeylon already has a backend, and it works. It was written quickly, by people who were right to write it quickly, and it has carried the product further than it had any business carrying it. We are not asking you to come and admire it. We are asking you to take ownership of it — to decide what stays, what gets rewritten, and what should never have existed — and then to build the version that holds up at ten times the traffic and twice the surface area.

This is the second senior engineering hire on the platform side, and the first with a clear mandate over the data layer. The scope is wide: the public API our web product and our forthcoming mobile app both consume, the ingestion pipelines that keep places, routes, timetables and prices current, the geospatial search that answers "what is near me and open right now," and the orchestration layer behind SerendAI. You will not own all of it alone forever. You will own it first.

The stack is TypeScript on Node, PostgreSQL with PostGIS, Redis, and a small amount of Python where the ML work lives. We are deliberate about this: one language across web, mobile and backend is how a team our size ships anything at all. If you want to introduce Go or Rust for a service where it genuinely earns its keep, make the case and we will listen. If you want to introduce a fourth database, the bar is higher.

What you will actually do

• Take ownership of the API. Versioning, contracts, error semantics, pagination, rate limits, auth. Two clients are about to depend on it in earnest, and one of them ships to app stores where a bad contract lives on a user's phone for months.
• Make the data trustworthy. Bus and train timetables change. Restaurants close. Prices move with the season. Build the ingestion, validation and reconciliation pipelines that let us say something true about the island, and know when we are about to say something false.
• Own geospatial search and ranking. Proximity, opening hours, travel time, weather, and whether a place is actually worth going to. Getting "near me" right is a database problem before it is a product problem.
• Build the orchestration behind SerendAI. Prompt routing, tool calls, caching, cost controls, graceful degradation when a model is slow or down. The interesting engineering in an AI product is almost never the model.
• Make it observable. Tracing, structured logs, meaningful alerts, and a dashboard that tells you what is wrong rather than that something is. We would rather find out from you than from a traveller in Ella.
• Set the operational standard. Migrations that run without downtime, backups that have actually been restored, a runbook someone else can follow at 3am, and an on-call rotation you would be willing to join. You will design it; you will not carry it alone.
• Draw the boundary with the clients. Our web codebase and the mobile app coming this year both want to share schemas, API clients and validation logic. Deciding what belongs in a shared package and what belongs behind the API is part of the job.
• Write at least one engineering post a year for the OneCeylon notebook — on your timeline, on a topic you choose.

What we think you will need

• Six or more years building backend systems, including several years on something you personally kept running in production.
• Real depth in PostgreSQL. Not "I have used an ORM" — you can read a query plan, you know why that index is not being used, and you have been burned by a migration at least once.
• Strong TypeScript, or strong Go or Java with a credible plan for being productive in TypeScript inside a month.
• API design judgement. You have made the versioning mistake before and you know what it cost.
• Experience with the unglamorous half: queues, retries, idempotency, backpressure, and what happens when a third-party provider starts returning 502s at eleven on a Friday night.
• The judgement to say no. We will ask you to make trade-offs every week. Seniority here means choosing what not to build.
• The habit of writing clearly. Good commit messages. Pull requests that explain themselves. Design docs that get decisions made.

Nice, but not needed

• PostGIS, or any serious geospatial work — routing, tiling, isochrones, proximity ranking.
• Having built an integration layer over messy third-party data: transport feeds, booking systems, payment providers, weather.
• Production experience with LLM applications — retrieval, evaluation, cost and latency control.
• Travel, hospitality, or local-services industry experience. Time zones, currencies and itineraries are more subtle than they look from the outside.
• Sinhala or Tamil language skills. Not required, but welcomed.

What you get in return

• LKR 500,000 to 800,000 per month, reviewed honestly every twelve months.
• Meaningful equity on a four-year vest. This is a founding-team engineering role, and the grant reflects that.
• Health insurance for you, your partner, and your children.
• A machine that runs the test suite in under a minute — your choice of configuration, plus whatever your local development environment genuinely needs, no approval process.
• Twenty-one days of paid leave, and a company that genuinely wants you to take all of them.
• A monthly book allowance, uncapped within reason and never audited.
• Enough authority to fix the things you find wrong, and enough runway to fix them properly rather than twice.

How to apply

Email careers@oneceylon.tech with the subject line OC-ENG-02. Attach your CV, a link to something concrete (a public repo, a schema you are proud of, a post-mortem you wrote), and a short paragraph on a system you inherited and what you changed first. No cover letter, no essays. We will write back within five working days, every time.