Sergey Kireev@kirejevFollow BadgesProblem Solving CertificationsCertificate: Problem Solving (Basic)VerifiedskillCertificate: Problem Solving (Intermediate)VerifiedskillWork Experiencekirejev has not updated employment details yet.Educationkirejev has not updated education details yet.Linkskirejev has not updated links details yet. Skillskirejev has not updated skills details yet.