diff --git a/tasks/borunov_v_complex_ccs/common/include/common.hpp b/tasks/borunov_v_complex_ccs/common/include/common.hpp
new file mode 100644
index 00000000..07cfd754
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/common/include/common.hpp
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <complex>
+#include <tuple>
+#include <vector>
+
+#include "task/include/task.hpp"
+
+namespace borunov_v_complex_ccs_seq {
+
+struct SparseMatrix {
+  int num_rows = 0;
+  int num_cols = 0;
+  std::vector<std::complex<double>> values;
+  std::vector<int> row_indices;
+  std::vector<int> col_ptrs;
+
+  bool operator==(const SparseMatrix &other) const {
+    return num_rows == other.num_rows && num_cols == other.num_cols && values == other.values &&
+           row_indices == other.row_indices && col_ptrs == other.col_ptrs;
+  }
+};
+
+using InType = std::vector<SparseMatrix>;
+using OutType = std::vector<SparseMatrix>;
+using TestType = std::tuple<int, int, int>;
+using BaseTask = ppc::task::Task<InType, OutType>;
+
+}  // namespace borunov_v_complex_ccs_seq
diff --git a/tasks/borunov_v_complex_ccs/info.json b/tasks/borunov_v_complex_ccs/info.json
new file mode 100644
index 00000000..1ce9ec05
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/info.json
@@ -0,0 +1,9 @@
+{
+  "student": {
+    "first_name": "Владислав",
+    "group_number": "3823Б1ПР3",
+    "last_name": "Борунов",
+    "middle_name": "Алексеевич",
+    "task_number": "1"
+  }
+}
diff --git a/tasks/borunov_v_complex_ccs/seq/include/ops_seq.hpp b/tasks/borunov_v_complex_ccs/seq/include/ops_seq.hpp
new file mode 100644
index 00000000..c89e5c2b
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/seq/include/ops_seq.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "borunov_v_complex_ccs/common/include/common.hpp"
+#include "task/include/task.hpp"
+
+namespace borunov_v_complex_ccs_seq {
+
+class BorunovVComplexCcsSEQ : public BaseTask {
+ public:
+  static constexpr ppc::task::TypeOfTask GetStaticTypeOfTask() {
+    return ppc::task::TypeOfTask::kSEQ;
+  }
+  explicit BorunovVComplexCcsSEQ(const InType &in);
+
+ private:
+  bool ValidationImpl() override;
+  bool PreProcessingImpl() override;
+  bool RunImpl() override;
+  bool PostProcessingImpl() override;
+};
+
+}  // namespace borunov_v_complex_ccs_seq
diff --git a/tasks/borunov_v_complex_ccs/seq/src/ops_seq.cpp b/tasks/borunov_v_complex_ccs/seq/src/ops_seq.cpp
new file mode 100644
index 00000000..124a6a25
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/seq/src/ops_seq.cpp
@@ -0,0 +1,97 @@
+#include "borunov_v_complex_ccs/seq/include/ops_seq.hpp"
+
+#include <algorithm>
+#include <cmath>
+#include <complex>
+#include <cstddef>
+#include <vector>
+
+#include "borunov_v_complex_ccs/common/include/common.hpp"
+
+namespace borunov_v_complex_ccs_seq {
+
+BorunovVComplexCcsSEQ::BorunovVComplexCcsSEQ(const InType &in) {
+  SetTypeOfTask(GetStaticTypeOfTask());
+  GetInput() = in;
+  GetOutput().resize(1);
+}
+
+bool BorunovVComplexCcsSEQ::ValidationImpl() {
+  if (GetInput().size() != 2) {
+    return false;
+  }
+  const auto &a = GetInput()[0];
+  const auto &b = GetInput()[1];
+  if (a.num_cols != b.num_rows) {
+    return false;
+  }
+  if (a.col_ptrs.size() != static_cast<size_t>(a.num_cols) + 1 ||
+      b.col_ptrs.size() != static_cast<size_t>(b.num_cols) + 1) {
+    return false;
+  }
+  return true;
+}
+
+bool BorunovVComplexCcsSEQ::PreProcessingImpl() {
+  const auto &a = GetInput()[0];
+  const auto &b = GetInput()[1];
+  auto &c = GetOutput()[0];
+
+  c.num_rows = a.num_rows;
+  c.num_cols = b.num_cols;
+  c.col_ptrs.assign(c.num_cols + 1, 0);
+  c.values.clear();
+  c.row_indices.clear();
+
+  return true;
+}
+
+bool BorunovVComplexCcsSEQ::RunImpl() {
+  const auto &a = GetInput()[0];
+  const auto &b = GetInput()[1];
+  auto &c = GetOutput()[0];
+
+  std::vector<std::complex<double>> col_accumulator(a.num_rows, {0.0, 0.0});
+  std::vector<int> non_zero_indices;
+  std::vector<bool> is_non_zero(a.num_rows, false);
+
+  for (int j = 0; j < b.num_cols; ++j) {
+    for (int b_idx = b.col_ptrs[j]; b_idx < b.col_ptrs[j + 1]; ++b_idx) {
+      int p = b.row_indices[b_idx];
+      std::complex<double> b_val = b.values[b_idx];
+
+      for (int a_idx = a.col_ptrs[p]; a_idx < a.col_ptrs[p + 1]; ++a_idx) {
+        int i = a.row_indices[a_idx];
+        std::complex<double> a_val = a.values[a_idx];
+
+        if (!is_non_zero[i]) {
+          is_non_zero[i] = true;
+          non_zero_indices.push_back(i);
+        }
+        col_accumulator[i] += a_val * b_val;
+      }
+    }
+
+    std::ranges::sort(non_zero_indices);
+
+    for (int i : non_zero_indices) {
+      if (std::abs(col_accumulator[i]) > 1e-9) {
+        c.values.push_back(col_accumulator[i]);
+        c.row_indices.push_back(i);
+      }
+      col_accumulator[i] = {0.0, 0.0};
+      is_non_zero[i] = false;
+    }
+    non_zero_indices.clear();
+
+    c.col_ptrs[j + 1] = static_cast<int>(c.values.size());
+  }
+
+  return true;
+}
+
+bool BorunovVComplexCcsSEQ::PostProcessingImpl() {
+  return true;
+}
+
+}  // namespace borunov_v_complex_ccs_seq
diff --git a/tasks/borunov_v_complex_ccs/settings.json b/tasks/borunov_v_complex_ccs/settings.json
new file mode 100644
index 00000000..0be0208f
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/settings.json
@@ -0,0 +1,10 @@
+{
+  "tasks": {
+    "all": "enabled",
+    "omp": "enabled",
+    "seq": "enabled",
+    "stl": "enabled",
+    "tbb": "enabled"
+  },
+  "tasks_type": "threads"
+}
diff --git a/tasks/borunov_v_complex_ccs/tests/functional/main.cpp b/tasks/borunov_v_complex_ccs/tests/functional/main.cpp
new file mode 100644
index 00000000..a8f6f6cd
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/tests/functional/main.cpp
@@ -0,0 +1,183 @@
+#include <gtest/gtest.h>
+
+#include <array>
+#include <cmath>
+#include <complex>
+#include <cstddef>
+#include <random>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "borunov_v_complex_ccs/common/include/common.hpp"
+#include "borunov_v_complex_ccs/seq/include/ops_seq.hpp"
+#include "util/include/func_test_util.hpp"
+#include "util/include/util.hpp"
+
+namespace borunov_v_complex_ccs_seq {
+
+namespace {
+
+using DenseMatrix = std::vector<std::vector<std::complex<double>>>;
+
+SparseMatrix GenerateRandomSparseMatrix(int num_rows, int num_cols, double sparsity) {
+  SparseMatrix mat;
+  mat.num_rows = num_rows;
+  mat.num_cols = num_cols;
+  mat.col_ptrs.assign(num_cols + 1, 0);
+
+  const int sparsity_seed = static_cast<int>(sparsity * 1000.0);
+  std::seed_seq seed{num_rows, num_cols, sparsity_seed};
+  std::mt19937 gen(seed);
+  std::uniform_real_distribution<double> dist_val(-10.0, 10.0);
+  std::uniform_real_distribution<double> dist_prob(0.0, 1.0);
+
+  for (int j = 0; j < num_cols; ++j) {
+    for (int i = 0; i < num_rows; ++i) {
+      if (dist_prob(gen) < sparsity) {
+        mat.values.emplace_back(dist_val(gen), dist_val(gen));
+        mat.row_indices.push_back(i);
+      }
+    }
+    mat.col_ptrs[j + 1] = static_cast<int>(mat.values.size());
+  }
+  return mat;
+}
+
+DenseMatrix BuildDense(const SparseMatrix &mat) {
+  DenseMatrix dense(mat.num_rows, std::vector<std::complex<double>>(mat.num_cols, {0.0, 0.0}));
+  for (int j = 0; j < mat.num_cols; ++j) {
+    for (int idx = mat.col_ptrs[j]; idx < mat.col_ptrs[j + 1]; ++idx) {
+      dense[mat.row_indices[idx]][j] = mat.values[idx];
+    }
+  }
+  return dense;
+}
+
+DenseMatrix MultiplyDenseMatrices(const DenseMatrix &left, const DenseMatrix &right) {
+  const int rows = static_cast<int>(left.size());
+  const int inner = rows == 0 ? 0 : static_cast<int>(left[0].size());
+  const int cols = right.empty() ? 0 : static_cast<int>(right[0].size());
+  DenseMatrix result(rows, std::vector<std::complex<double>>(cols, {0.0, 0.0}));
+
+  for (int i = 0; i < rows; ++i) {
+    for (int j = 0; j < cols; ++j) {
+      for (int k = 0; k < inner; ++k) {
+        result[i][j] += left[i][k] * right[k][j];
+      }
+    }
+  }
+
+  return result;
+}
+
+SparseMatrix BuildSparseFromDense(const DenseMatrix &dense) {
+  SparseMatrix c;
+  c.num_rows = static_cast<int>(dense.size());
+  c.num_cols = dense.empty() ? 0 : static_cast<int>(dense[0].size());
+  c.col_ptrs.assign(c.num_cols + 1, 0);
+
+  for (int j = 0; j < c.num_cols; ++j) {
+    for (int i = 0; i < c.num_rows; ++i) {
+      if (std::abs(dense[i][j]) > 1e-9) {
+        c.values.push_back(dense[i][j]);
+        c.row_indices.push_back(i);
+      }
+    }
+    c.col_ptrs[j + 1] = static_cast<int>(c.values.size());
+  }
+
+  return c;
+}
+
+SparseMatrix MultiplyDense(const SparseMatrix &a, const SparseMatrix &b) {
+  DenseMatrix dense_a = BuildDense(a);
+  DenseMatrix dense_b = BuildDense(b);
+  DenseMatrix dense_c = MultiplyDenseMatrices(dense_a, dense_b);
+  return BuildSparseFromDense(dense_c);
+}
+
+}  // namespace
+
+class BorunovVRunFuncTestsThreads : public ppc::util::BaseRunFuncTests<InType, OutType, TestType> {
+ public:
+  static std::string PrintTestParam(const TestType &test_param) {
+    return std::to_string(std::get<0>(test_param)) + "_" + std::to_string(std::get<1>(test_param)) + "_" +
+           std::to_string(std::get<2>(test_param));
+  }
+
+ protected:
+  void SetUp() override {
+    TestType params = std::get<static_cast<std::size_t>(ppc::util::GTestParamIndex::kTestParams)>(GetParam());
+    int m = std::get<0>(params);
+    int k = std::get<1>(params);
+    int n = std::get<2>(params);
+
+    SparseMatrix a = GenerateRandomSparseMatrix(m, k, 0.2);
+    SparseMatrix b = GenerateRandomSparseMatrix(k, n, 0.2);
+
+    input_data_ = {a, b};
+    expected_output_ = {MultiplyDense(a, b)};
+  }
+
+  bool CheckTestOutputData(OutType &output_data) final {
+    if (expected_output_.size() != output_data.size()) {
+      return false;
+    }
+    const auto &expected = expected_output_[0];
+    const auto &actual = output_data[0];
+
+    if (expected.num_rows != actual.num_rows || expected.num_cols != actual.num_cols) {
+      return false;
+    }
+    if (expected.col_ptrs != actual.col_ptrs) {
+      return false;
+    }
+    if (expected.row_indices != actual.row_indices) {
+      return false;
+    }
+    if (expected.values.size() != actual.values.size()) {
+      return false;
+    }
+
+    for (std::size_t i = 0; i < expected.values.size(); ++i) {
+      if (std::abs(expected.values[i] - actual.values[i]) > 1e-6) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  InType GetTestInputData() final {
+    return input_data_;
+  }
+
+ private:
+  InType input_data_;
+  OutType expected_output_;
+};
+
+namespace {
+
+TEST_P(BorunovVRunFuncTestsThreads, MatmulTests) {
+  ExecuteTest(GetParam());
+}
+
+const std::array<TestType, 3> kTestParam = {
+    std::make_tuple(10, 10, 10),
+    std::make_tuple(20, 15, 25),
+    std::make_tuple(5, 30, 5),
+};
+
+const auto kTestTasksList = std::tuple_cat(
+    ppc::util::AddFuncTask<BorunovVComplexCcsSEQ, InType>(kTestParam, PPC_SETTINGS_borunov_v_complex_ccs));
+
+const auto kGtestValues = ppc::util::ExpandToValues(kTestTasksList);
+
+const auto kPerfTestName = BorunovVRunFuncTestsThreads::PrintFuncTestName<BorunovVRunFuncTestsThreads>;
+
+INSTANTIATE_TEST_SUITE_P(SparseMatrixTests, BorunovVRunFuncTestsThreads, kGtestValues, kPerfTestName);
+
+}  // namespace
+
+}  // namespace borunov_v_complex_ccs_seq
diff --git a/tasks/borunov_v_complex_ccs/tests/performance/main.cpp b/tasks/borunov_v_complex_ccs/tests/performance/main.cpp
new file mode 100644
index 00000000..375e0fd4
--- /dev/null
+++ b/tasks/borunov_v_complex_ccs/tests/performance/main.cpp
@@ -0,0 +1,74 @@
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <vector>
+
+#include "borunov_v_complex_ccs/common/include/common.hpp"
+#include "borunov_v_complex_ccs/seq/include/ops_seq.hpp"
+#include "util/include/perf_test_util.hpp"
+
+namespace borunov_v_complex_ccs_seq {
+
+namespace {
+
+SparseMatrix GenerateSparseMatrixPerf(int num_rows, int num_cols, int non_zeros_per_col) {
+  SparseMatrix mat;
+  mat.num_rows = num_rows;
+  mat.num_cols = num_cols;
+  mat.col_ptrs.assign(num_cols + 1, 0);
+
+  int step = std::max(1, num_rows / non_zeros_per_col);
+
+  for (int j = 0; j < num_cols; ++j) {
+    for (int i = 0; i < num_rows; i += step) {
+      mat.values.emplace_back(static_cast<double>(i + 1), static_cast<double>(j + 1));
+      mat.row_indices.push_back(i);
+    }
+    mat.col_ptrs[j + 1] = static_cast<int>(mat.values.size());
+  }
+  return mat;
+}
+
+}  // namespace
+
+class BorunovVRunPerfTestThreads : public ppc::util::BaseRunPerfTests<InType, OutType> {
+  InType input_data_;
+
+  void SetUp() override {
+    int m = 200000;
+    int k = 200000;
+    int n = 200000;
+
+    SparseMatrix a = GenerateSparseMatrixPerf(m, k, 20);
+    SparseMatrix b = GenerateSparseMatrixPerf(k, n, 20);
+
+    input_data_ = {a, b};
+  }
+
+  bool CheckTestOutputData(OutType &output_data) final {
+    return output_data.size() == 1;
+  }
+
+  InType GetTestInputData() final {
+    return input_data_;
+  }
+};
+
+TEST_P(BorunovVRunPerfTestThreads, RunPerfModes) {
+  ExecuteTest(GetParam());
+}
+
+namespace {
+
+const auto kAllPerfTasks =
+    ppc::util::MakeAllPerfTasks<InType, BorunovVComplexCcsSEQ>(PPC_SETTINGS_borunov_v_complex_ccs);
+
+const auto kGtestValues = ppc::util::TupleToGTestValues(kAllPerfTasks);
+
+const auto kPerfTestName = BorunovVRunPerfTestThreads::CustomPerfTestName;
+
+INSTANTIATE_TEST_SUITE_P(RunModeTests, BorunovVRunPerfTestThreads, kGtestValues, kPerfTestName);
+
+}  // namespace
+
+}  // namespace borunov_v_complex_ccs_seq