I’m Piotr Sienkiewicz,
Individual contributor with a love for startup chaos, who grew into leadership to help teams succeed. I've successfully scaled two startups from small teams to market leaders in their industries and led culturally diverse teams along the way.
Logical by nature, driven by data, grounded in research.
Product Manager
Global Gaming Services d.o.o. (GameBoost.com)
2023 - 2025
I played a key role in scaling the team from 8 to 35+ full-time employees and growing the platform from 50K to over 1M monthly visits. Led market and games research, reshaped the company vision, and launched 7 new core product categories, 50+ games, and 200+ features. Mentored juniors into key roles (data and marketing), optimized workflows across departments, and managed a culturally diverse, cross-functional team of 10 on-site.
REFERENCES
Kristijan Salijević
CEO & Founder
Piotrek has been an essential part of our journey through 2023 and 2024. From product planning and execution, cross-department cooperation, he helped us to pivot from a League boosting website to the big gaming marketplace we are today. His hardwork, creativity, data analysis and helping multiple departments level up has left us with a great foundation going forward. We wouldn't be here today without him, Piotrek is a part of GameBoost history and a crucial one.
Youssef
CTO
Working with Piotr was an absolutely incredible experience. Together, we built and launched numerous projects, achieving results that would have been unimaginable without his vision and drive. Piotr’s dedication, creativity, and leadership played a crucial role in our success, and collaborating with him always felt natural and effortless.
Influencer Marketing
Tapin.GG
Q2 - Q3 2023
Signed and collaborated with 50+ top YouTube gaming creators, wrote original brand-driven scripts (some reaching 1M+ views), and built lasting influencer partnerships.
REFERENCES
Kostas Mavromatis
General Manager
If you ever get the chance to work with Piotr, just take it. He's insanely creative, sharp and he delivered some of the most successful campaigns while helping me to build strong foundation and relationships with all our freelancers. Huge recommendation.
Operations Manager
Tapin.GG
Q1 2023
Hired, verified, and managed over 100 freelancers on the platform, significantly improving order pick time and overall product quality. Oversaw freelancer performance and handled quality control across all stages of delivery.
Personal Experience
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Throughout my life, I've run a bunch of personal projects. Including a 3 year e-commerce business, generating leads for banks through 2 years of affiliate marketing, helping build from scratch and manage the world's largest calisthenics community, coaching over 500 students as a personal trainer, reaching the top 300 globally in the world's most competitive esport game, League Of Legends, and writing my own e-book, which sold a few hundred copies.
Data (business & marketing & SEO)
Expert
Data aligns with the logical nature of my brain, and it's the core of my business decisions. I'm highly skilled at analyzing complex marketing, business, financial, and SEO data to drive solutions.
Copywriting
Advanced
I've been using writing to sell for years - through affiliate, my own e-book, building & running communities, and managing teams online. It's also something I really enjoy doing.
SEO
Advanced
My logical brain and passion for copywriting both enjoy how complex SEO is. I’ve applied it in real-world projects and stay up to date with the latest trends and updates.
Marketing
Skiled
I'm an expert in creative marketing, especially when it comes to content strategies like YouTube partnerships. However, I'm still growing in Facebook and Google Ads. I can create, analyze, and manage basic to semi-advanced campaigns, though I wouldn't call myself a senior by any means
