Bonaventure OgetoBy Bonaventure Ogeto|

What Fintech Employers in Nairobi Actually Test For

Nairobi fintech technical assessments typically include: 1) Build an M-Pesa Daraja STK push integration with callback handler. 2) Paystack Kenya checkout with M-Pesa channel selection. 3) System design: design a mobile money disbursement system for 50,000 users. 4) CBK regulation knowledge: Payment Service Provider licensing, DPA 2019, KRA TIN requirements. 5) Mobile money UX: how to handle STK push timeout, what happens when the user closes the M-Pesa PIN prompt.

Common Technical Assessments in Nairobi

AssessmentWhat They BuildWhat They Look For
M-Pesa STK Push integrationExpress endpoint: initiate STK push, receive callback, update DBDaraja API knowledge, callback handling, ResultCode parsing (0 = success)
Paystack Kenya checkoutCheckout with card + M-Pesa channel options, webhook handlerChannel routing, Kenya-specific UX, idempotency
System design: wallet/ledgerDesign a mobile wallet with deposits, withdrawals, transfersDouble-entry ledger, balance consistency under concurrent writes, audit log
Mobile money failure handlingGiven an STK callback handler, find the missing edge casesResultCode 1032 (user cancelled), 1037 (timeout), insufficient balance (1), duplicate transaction
API integration debugDebug a broken Daraja integrationTimestamp format, Base64 encoding, password generation, wrong endpoint URL

Kenyan Payment Domain Knowledge They Test

  • M-Pesa Daraja API — STK Push (C2B), B2C (vendor payouts), B2B, Express Query, Transaction Reverse. Know the password format (Base64(shortcode + passkey + timestamp)).
  • CBK PSP licensing — Central Bank of Kenya Payment Service Provider framework. What is a PSP? What license does a company need to process payments in Kenya?
  • Kenya DPA 2019 — Data Protection Act, ODPC registration, privacy notice requirements, DPIA for high-risk processing.
  • KRA PIN — Kenya Revenue Authority PIN required for business registration and tax compliance.
  • PesaLink — interbank mobile money transfer platform. Know the difference between M-Pesa P2P and PesaLink interbank transfers.
  • Kenyan gateway landscape — Paystack Kenya, IntaSend, Pesapal, DPO Pay, Cellulant — what each supports.

Learn More

See system design: payment service to prepare for the common Nairobi design question.

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Key Takeaways

  • M-Pesa Daraja knowledge is required, not optional, for most Nairobi fintech engineering roles.
  • Know the STK push flow: InitiateTransaction → callback → verify (ResultCode = 0 for success).
  • Understand the CBK PSP licensing framework and what it requires from payment companies.
  • Paystack Kenya + M-Pesa combination knowledge distinguishes Kenyan market specialists.
  • Know mobile money UX failure modes: STK timeout, user cancels, insufficient M-Pesa balance.

Frequently Asked Questions

What Nairobi fintech companies are worth targeting for payment engineering roles?
Safaricom (M-Pesa Africa engineering team), KCB Group technology division, Equity Bank digital, Cellulant, Pesapal, IntaSend, Craft Silicon, Africa's Talking, and any Nairobi-based startup processing payments. Remote roles at Chipper Cash, Flutterwave, or Paystack that serve the Kenyan market also value Daraja and Kenyan market knowledge.
How well do I need to know M-Pesa Daraja to interview at Nairobi fintechs?
Well enough to implement a complete STK push flow from scratch, including: generating the password (Base64 shortcode+passkey+timestamp), the callback URL, parsing ResultCode (0 = success, 1032 = user cancelled, 1037 = timeout), and querying transaction status via Express Query. If you can implement it without referring to documentation, you are ready. If you have to look up the password format, spend another week on Daraja before interviewing.
Should I learn Paystack Kenya or M-Pesa Daraja first for Nairobi interviews?
M-Pesa Daraja first. It is the more complex and more differentiated skill — everyone can follow the Paystack docs, but Daraja has more gotchas (Base64 password, OAuth token expiry, callback URL validation, STK vs. C2B registration). Once you know Daraja deeply, Paystack Kenya integration is straightforward. Showing both in your portfolio is the strongest Nairobi-market combination.

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