𝗠𝘆 𝗛𝗢𝗡𝗘𝗦𝗧 𝗛𝗡𝗚 𝗜𝗡𝗧𝗘𝗥𝗡𝗦𝗛𝗜𝗣 𝗘𝗫𝗣𝗘𝗥𝗜𝗘𝗡𝗖𝗘

𝗠𝘆 𝗛𝗢𝗡𝗘𝗦𝗧 𝗛𝗡𝗚 𝗜𝗡𝗧𝗘𝗥𝗡𝗦𝗛𝗜𝗣 𝗘𝗫𝗣𝗘𝗥𝗜𝗘𝗡𝗖𝗘

I spent two years as a Laravel developer. I felt stuck. I realized I did not know much about real programming. I decided to learn Javascript from scratch. That is how I found HNG.

HNG is a remote, intensive program. It gives you real engineering work from day one. There is no hand-holding. You get tasks, deadlines, and a Slack channel. It is a sink or swim environment. The pressure shows you how you think when things break.

I want to share two specific tasks from my time there.

𝗧𝗮𝘀𝗸 𝟭: 𝗥𝗲𝘁𝗿𝘆 𝗘𝗻𝗴𝗶𝗻𝗲 (𝗜𝗻𝗱𝗶𝘃𝗶𝗱𝘂𝗮𝗹)

I used Node.js and raw SQL with better-sqlite3. I built a schema for jobs, status, and error logs.

The problem: I hit a race condition. I tried to check a job status before processing it. But the check and the update were not atomic. Two instances could read the same pending job at the same time.

The fix: I used SQLite BEGIN IMMEDIATE transactions. I made the status check and update a single atomic operation. I used the synchronous nature of better-sqlite3 to make the locking reliable.

Lessons learned:

• Concurrency bugs are hard to debug. They do not happen every time.
• You must understand your tools. I thought the library's synchronous nature was a limit. It was actually the solution.

𝗧𝗮𝘀𝗸 𝟮: 𝗦𝗸𝗶𝗹𝗹𝗯𝗿𝗶𝗱𝗴𝗲 𝗔𝘀𝘀𝗲𝘀𝘀𝗺𝗲𝗻𝘁 (𝗧𝗲𝗮𝗺)

I worked on the backend for a personal assessment flow. I handled validation, failure handling, and API contracts.

The problems:

• Case mismatch: The frontend expected snake_case. The backend sent camelCase. We lost time debugging why fields were undefined.
• Mid-build changes: The PMs changed the requirements halfway through. We had to move question management from the frontend to the backend. This forced a redesign of our data model.
• Testing struggles: My early end-to-end tests failed constantly. I struggled with test isolation and state.

Lessons learned:

• Use shared, written API contracts. Review them before coding starts.
• Document the impact of spec changes immediately.
• Tests are not just for green checkmarks. The failures tell you how your code actually works.

These tasks were not the most complex algorithms. But they made me a better engineer. I learned more in these two months than I have in a long time. HNG does not protect you from hard problems. That is why it works.

Source: https://dev.to/joyigbonekwu/behind-the-green-tests-my-honest-hng-internship-experience-3hn8