Career Change at 30: To Data Engineer

I was a food developer who had launched coffee beverage products.

Now, I’m an IT developer(more specifically, data engineer).

About 3 years ago, I just chose to do something other than what I was doing. Frankly, it was not sure. My focus was a ‘short pause’ that would bring the diversity in my career. To be mentally concrete on that action, I harshly felt the situation and pierce my mind deeply with the brilliant changes out of the field. Feeling separated, changing career seems to get worth to experience in this changing world.

When I was a food developer 3 years ago

I started my first career in the food industry. The company that I worked for is small-size and its sales heavily depend on the retail industry, especially Korean convenience store conglomerates; GS25, CU, and 7-Eleven. So, looking back, the company put more intense on the sales and the R & D itself is not the main concern.

Even though there’s some hardship like pushing researchers to make samples all night long for the product line-up meeting at those companies, sometimes I was just fluttered by the fact that I made a country-wide beverage product. And, I learned how to set up a whole manufacturing process: collecting resources, controlling and pre-processing them(or out-sourcing the process), preparing product prototype and following the legal standard(I think that this part helps me later a little bit when I’m building ‘Data Pipeline’ as a data engineer).

Make a Trigger

I think that I’ve felt it how to make it before unconsciously. I tried to be more professional in that field. But that had also persuaded me to fire a trigger saying ‘You have done enough, you did many things fervently but you seem unsatisfied’. So, to quit was a physically natural choice to minimize the regret. The fact that I’ve eagerly pushed myself on that field, makes me do not look back without any remnants after that step.

8 Months Prep

I spent 8 months to change the job. What I did is the following:

  • Start Korea Cyber University BS on Software Engineering(4 months before I quit): kind of PoC that I’m in this field sincerely and in a long-term strategy
  • Take a boot camp course on data scientist: To make a start point. To learn the tacit knowledge and base common sense pervasive in the IT field.
  • Study Python, SQL, Basic HTML & CSS, Linux, Cloud through Coursera, and others(like Treehouse) & books: To learn how to study the things in needs on myself, spontaneously.
  • Prepare a resume(Github, Project) for the interviews: To prove that I’m an MVP for the market.

It was a wise choice to take a boot camp course at the beginning. The course covered Python Basics, Calculus & Optimization, Probability & Statistics, Cloud, Database in 4 months. I just rushed to coding without a deep understanding of the concepts. I also made a code to study some DS things by trying Kaggle problems and took an online course for a full stack developer.

Among that stuff, I try to simplify things to learn so that it would be more productive anyhow:

  1. Python & English: Stick to the Official Languages that I picked. Study DB, Web, OS system, Data Structure, and Algorithm only with Python & English.
  2. Align things for the purpose: Learn for project, project and learning logs for resume

For the first one, you can expand your knowledge by trying to find the replacements in another language like this case(Java to Python).


I’m honored that I can have a chance to work in this IT field as a Data Engineer. Currently, I continue my career in an e-commerce company and always try to get in touch with other amazing changes happening here. Things that top on my head is:

  • Learn Java from the bottom
  • Read more comprehensive books in detail: Operating System Concepts, Code Completes, Hadoop The Definitive Guide, Hive Essentials, Data Warehouse, The Compression, Site Reliability Engineering, Data Related Books on Oreilly
  • AWS Certification
  • Finish Online Lecture that I already bought on Udemy: Kotlin, Hacking, Network Programming, Terraform, Angular, Go …
  • Writings: Medium & Mentoring

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store