https://biya.com.ng/blog Engineering write-ups from the team building chat-native payments in Nigeria. en https://biya.com.ng/blog/engineering/our-default-value-was-not-a-valid-value https://biya.com.ng/blog/engineering/our-default-value-was-not-a-valid-value A field defaulted to null. The list of allowed values did not include null. Every new merchant signup failed at the last step. Sun, 29 Mar 2026 00:00:00 GMT Fadoski https://biya.com.ng/blog/engineering/the-error-message-was-pointing-at-the-wrong-layer https://biya.com.ng/blog/engineering/the-error-message-was-pointing-at-the-wrong-layer Staff could not submit a payment request. The error pointed at MongoDB. The request had never reached MongoDB, or the backend, or the network. Wed, 22 Apr 2026 00:00:00 GMT Fadoski https://biya.com.ng/blog/engineering/payments-in-a-chat-window https://biya.com.ng/blog/engineering/payments-in-a-chat-window No app to download means no client state, no session, and no screen you control. Here is what that actually costs, and the three-outcome rule that took us longest to learn. Sun, 30 Aug 2026 00:00:00 GMT Fadoski https://biya.com.ng/blog/engineering/failover-hid-a-total-outage https://biya.com.ng/blog/engineering/failover-hid-a-total-outage A provider rejected every data purchase we sent it for weeks. Every customer was served. Nothing alerted. The fix was one log line. Sun, 30 Aug 2026 00:00:00 GMT Fadoski https://biya.com.ng/blog/engineering/one-service-talks-to-every-provider https://biya.com.ng/blog/engineering/one-service-talks-to-every-provider Our products used to talk to every airtime, data, electricity and TV provider themselves, and each provider has its own login, its own plan names, its own status codes and its own idea of when to tell you the outcome. Now one service does all of that, and the products send it a request in their own words and get back a uniform answer. Sun, 13 Sep 2026 00:00:00 GMT Fadoski