About us
A training institute that became an engineering company
We started in 2021 to close the gap between what students are taught and what the industry expects. The client work grew out of the teaching, and the two have fed each other ever since.
Our story
How it started
Substring Technologies began in January 2021, out of a straightforward observation: there was a gap between what students were taught and what the industry expected them to already know.
It was founded by Durgesh Kumar Tiwari, who graduated with a B.Tech in 2017 and took a placement at an MNC in Bangalore — then left it to work on the problem directly. An early venture did not survive a partnership disagreement, but the teaching did. A YouTube channel started as a side project and found an audience quickly.
Demand from that audience for structured, in-depth material turned into online courses, and the courses turned into a company. Substring now runs summer training programmes in colleges, corporate upskilling, internships and live classes on current technologies.
Alongside the teaching, the same engineers build and maintain software for businesses — which is what keeps the course material tied to how the work is actually done.
What we are trying to do
Bridge the gap between theoretical knowledge and real-world application through hands-on training.
Make high-quality programming education accessible to aspiring engineers across the country.
Build a community of developers equipped to solve hard problems, not just pass interviews.
Contribute to a digitally capable workforce that can lead the technology work of the next decade.
What we hold to
Practical over theoretical
Everything we teach is something we have shipped. If it has no place in real delivery work, it has no place in the curriculum.
Accessible by default
Over 1,300 tutorials published free. Paid programmes add structure, feedback and mentorship — not access to the basics.
Learner-centric
Small batches, direct mentorship and doubt-clearing outside class hours. Progress is measured by what you can build, not attendance.
Community
Learners, alumni and mentors who stay in touch long after a programme ends, and hire from each other.
Team
The people behind it
A small team, which is why you talk to the people doing the work.
Durgesh Tiwari
CEO
Leading the vision and strategy.
M P Tiwari
Director
Guiding operational excellence.
Shruti Dixit
Developer
Building robust solutions.
Ranjana Chaurasiya
Content Team Head
Curating world-class learning content.
Community
Most of what we teach is published free
Years of tutorials, walkthroughs and Q&A, open to anyone. It is also the easiest way to judge how we teach before you pay for anything.
Come and see the place
Our Lucknow centre is open through the week. If you are nearby, drop in — otherwise a call works just as well.