Free · 44 templates for real work · 10 labs · 56 courses
হাতে-কলমে শিখুন।
Open a template for the job on your desk, like a month-end SQL report, a PRD, a cash-flow model or a runbook. Use your own data, export the result, and the lesson behind it is one click away.
Tools
Start from a template for a job you do anyway, use your own data, and take the result with you. Every template links to the lesson behind it.
For dba, backend developer, data analyst, 4 templates
Real PostgreSQL in your browser for the queries work needs: month-end reports, retention, data-quality checks and schema design, on your own CSV or schema or on sample databases from your industry. Read plans and time indexes too.
Start from a template for real work
In 40 seconds
or a route for your role
22 routes
A route is the courses a job needs, in the right order, with the tools that job uses. Finish them all for the path certificate.
New to tech? Start here and build the foundations every role needs.
Inside a lesson
Every lesson runs the same stops, so you always know where you are, and it ends in a tool you can use at work.
From Caching. Commit to an answer before you see the reasoning.
Quick check
Which of these caches can you not clear from your side once a copy is stored there?
article:1001 is a hit.Nadia, a senior engineer, talks every lesson through with Imran, a product manager. If the lesson is open, the page follows along to each diagram they mention. All 323 episodes, about 64 hours.
Pass a course’s final exam (random questions plus hands-on tasks checked on the server) for a skill certificate with your score. Finish every lesson and a reviewed capstone for the course certificate. Both are free, have their own verify page, and go on LinkedIn in one click.
Certificate of completionThis certifies that
Your name here
has completed the course
How the Web Works
The course map
Each station is a course and fills in as you finish its lessons. Where two lines meet, a course counts for both.
Good first stations
Learners
Templates you finish, lessons, checks and lab challenges earn XP and badges, a streak keeps you going, weekly leagues put you next to people at your level, and your Builder rank climbs as you go.
Moved from a commerce degree into a first backend job: every stop of Building APIs with Node.js, SQL Lab templates every week, and the lesson podcasts on the bus to work.
Turned manual test checklists into regression suites in the QA Lab, cleared the Bug Hunter mutation campaign and earned the Software Testing and QA certificate.
Writes every PRD from the Product & BA Lab template now, maps the refund process as a swimlane before each sprint and exports the roadmap as Markdown for the team.
Built a weekly KPI notebook on her own sales CSV in the Data Lab, followed the diagrams in Data Analysis with Excel, Python & AI, and exports the charts for Monday meetings.
Modelled unit economics and a 12-month cash flow with scenario sliders in the Finance Lab, then took Finance for Tech Teams to read the numbers before talking to investors.
Followed the DevOps / SRE Engineer path from pipelines to on-call, fixed the broken pipeline in the DevOps Lab challenges and holds a top spot in the weekly league.
Plans
Kolom Plus adds every challenge, unlimited exports and something new each week; Kolom Premium adds a mentor. Finish half a course and your first month of Plus is free.
৳0 forever
৳100 per 30 days
৳1,500 per 30 days
Open a tool for the job on your desk, or answer a few questions and we’ll point you at the right first route.
One lesson, one diagram and one interview question a week. A short letter every Thursday, with no tracking pixels and one click to leave.