Mark Koslow

Product Leader

Hi, I'm Mark

I'm a seasoned Product Manager with a decade of Product and Engineering experience. I can help you build products that achieve your business goals and delight your customers.

How I can help


I've built and launched successful products for 5-person startups and $100M+ businesses. My adaptable approach seamlessly integrates into product teams of any size and stage.

Fractional Product Lead
I collaborate with your team to drive product strategy, find product-market fit, and understand the competitive landscape.
- OKRs and goal-setting
- Finding product-market fit
- Product vision
- Growth strategy
- Improving product development process
- Retention & engagement stategies
- Competitive analysis
- Opportunity assessment
- Market research

Embedded PM / Technical PM
I work with your team throughout the product development process, from planning and ideation to launch and iteration.
- User research
- OKRs & goal-setting
- Technical planning & architecture
- Prioritization & roadmaps
- PRDs & wireframes
- A/B testing
- Data analysis
- Sprint planning & execution
- Project & stakeholder management

About Me

PM, Engineer, Writer

Hi from Los Angeles! After 7 years in NYC, I moved to the West coast after the pandemic. Most recently, I was a Product Manager at Reforge, a career development platform for top-tier professionals in tech. Before that, I helped lead product efforts at Lambda School (now BloomTech) and led engineering efforts for a new product line at TeachersPayTeachers (acq. by IXL). I have a strong technical background with a degree in Computer Science and 5+ years of full-time engineering experience. In my free time, you can find me writing my newsletter, reading about current affairs, or practicing meditation.


Rishin Banker

Head of Product @ Maven

"Mark was an invaluable partner in taking our product from 0->1. He made a huge impact by championing both bold new directions (e.g. alternate business models) and high-ROI pain relievers (e.g. internal admin tools). He has a rare knack for understanding how the business works and how the sausage is made. Would strongly recommend for anyone looking to level up their product."

Helen Smith

VP, Product @ Reforge

"Mark is one of the best product managers that I’ve had the opportunity to work with. He is a hardworking, strategic, and technical partner that can break down even the most complex problems with ease and come up with creative solutions that map to greater company objectives. In addition to his strong hard skills, Mark is also an absolute joy to work alongside. He is generous with his feedback and ideas, and makes all around him better too."


2022 - 2023


Reforge is a Series B venture-backed career development platform for top-tier professionals in tech. I led our search and discovery efforts, revamped the core content viewing experience, and repackaged our existing content library to better fit the needs of our users.

2019 - 2021

BloomTech (fka Lambda School)

BloomTech has helped over 4K+ alumni land a career in tech. 90% of their 2021 job-seeking graduates landed jobs with a median salary increase of $27,500. I owned all student-facing applications from enrollment through graduation for 1,000+ concurrent students and migrated the school onto Canvas, a Learning Management System.

2017 - 2019

Teachers Pay Teachers (acq. by IXL)

85% of U.S. teachers and 7M+ teachers worldwide use TPT to buy, sell, and share original educational resources, with over 1B resource downloads. I helped lead engineering efforts for a brand new B2B subscription product that redefined our target customer, business model, and product offering, which now generates $15M+ in ARR. TPT was backed by Spectrum Equity and Tiger Global and acquired by IXL Learning.


Duke University

Graduated with B.A. in Computer Science, 3.9/4.0

Interested in working together?

Want to work together?

Reach out via this form or email me