Senior Backend and API Developer

Candiid Labs is a software development company. We build products in AI, health tech, fintech and gaming.

We are building an open-world mobile game set in real Lagos. It uses real streets, real time of day, rush hour and public holidays. Players earn in-game money as they play, and the top players win real cash prizes every week. The game runs in the browser and as Android and iPhone apps.

The game is live and working. Now we want to take it close to GTA-level realism, and we need two strong developers to do it with us over the next 60 days and beyond.

The role is remote, with a preference for candidates in Nigeria or who know Lagos well.

What you will do

• Own the backend: Firebase (Firestore, Realtime Database, Auth) and Cloud Functions in Node.js or TypeScript.
• Build and document the game’s APIs for:
• sign-in and profiles
• wallet and weekly scores
• leaderboards
• prizes
• chat and crews
• events
• in-game shop
• Keep the prize system fair. Check scores on the server, cap daily earnings, catch bots and duplicate accounts, and make sure only verified real players get paid.
• Integrate payments and payouts:
• Paystack or Flutterwave for in-app purchases
• webhooks
• bank payouts to winners
• basic identity checks
• Build multiplayer services: presence, chat moderation and live events.
• Keep running costs low as players grow, and decide when parts of the system should move to PostgreSQL.
• Set up staging, monitoring, alerts, backups and logs.
• Support the admin dashboard: player lookups, flagged chat, payout approvals and daily reports.

What you need

• At least 4 years of backend development in Node.js or TypeScript.
• Production experience with Firebase or Google Cloud, including data modelling, security rules, Cloud Functions and Auth.
• Experience building payment flows with webhooks, so a payment is never charged or paid twice.
• A strong security mindset: auth, rate limiting, input checks, abuse prevention, and never trusting the client.
• Solid SQL and PostgreSQL skills.
• You write clear API docs and tests.

Nice to have

• Experience with fintech, fantasy sports or real-money gaming backends.
• Nigerian payment providers and bank payout APIs.
• Fraud detection, or real-time systems at scale.
• Shipping apps to the Play Store and App Store.

Trial task (2 to 3 days)

• Build a Cloud Function that takes a player’s end-of-session score, rejects impossible gains, applies a daily cap, updates the weekly leaderboard and writes an audit log.
• Add a payment webhook that credits a purchase exactly once, even if the provider sends the same event three times.

What we offer

• Competitive pay, with the possibility of equity for the right people.
• A small, fast team that ships every day.
• The chance to build the biggest game ever made about Lagos.

How to apply
Send your CV and links to work you built yourself to [email protected], with the role in the subject line. Include a GitHub repo or a system you can walk us through. Applications without real work samples will not be reviewed.

Job Type: Full-time

Pay: ₦350,000.00 - ₦450,000.00 per month

Work Location: Remote